The American Eel (Anguilla rostrata) has long been regarded as a panmictic fish and has been confirmed as such in the northern part of its range. In this paper, we tested for the first time whether panmixia extends to the tropical range of the species. To do so, we first assembled a reference genome (975 Mbp, 19 chromosomes) in order to support both this study and future research. To test for population structure, we estimated genotype likelihoods from low coverage whole genome sequencing of 460 American Eels, collected at 21 sampling sites (in seven geographic regions) ranging from Canada to Trinidad and Tobago. We estimated genetic distance between regions, performed ADMIXTURE-like clustering analysis and multivariate analysis, and found no evidence of population structure. In addition, two genomic regions with putative inversions were observed, both geographically widespread and present at similar frequencies in all regions. We discuss the implications of lack of genetic population structure for the species. Our results are key for the future genomic research in the American Eel and the implementation of conservation measures throughout its geographic range.

Acquiring data on rare and threatened species can be challenging, particularly in remote areas. However, environmental DNA (eDNA) surveys offer a less effort-intensive method of detecting these species than more traditional fish sampling methods. In our study, we focused on the Yaqui Catfish (Ictalurus pricei), an endangered freshwater fish endemic to the Sonoran desert (Arizona, US and Sonora, Mexico), and the non-native Channel Catfish (Ictalurus punctatus). To detect these species, we developed and employed mitochondrial DNA markers and a stratified random sampling method. We collected water samples for eDNA detection from 35 locations in the Yaqui River basin in Mexico. Using a hierarchical Bayesian formulation of a co-occurrence model, we examined the effects of interacting species, where one species is dominant (Channel Catfish) and the other subordinate (Yaqui Catfish), while allowing for the effects of covariates to be specified on species occupancy and detection. Our best model included the influence of non-native Channel Catfish on detecting native Yaqui Catfish. Moreover, we found that detection of Channel Catfish was negatively related to water temperature and elevation, but positively related to substrate size. Occupancy of Yaqui Catfish was best explained by stream permanence (i.e., higher rates of stream discharge and low probabilities of the reach drying) and forested areas. Channel Catfish were also associated with stream permanence (i.e., low probabilities of the stream reach drying and larger upstream watershed areas) and conifer and shrub-dominated landscapes. Non-native Channel Catfish eDNA was found in all but five locations where Yaqui Catfish eDNA was detected, indicating a high likelihood of interaction and hybridization. The threat of hybridization to the already endangered Yaqui Catfish highlights the need to secure remaining populations for their long-term survival.

Biodiversity collections are experiencing a renaissance fueled by the intersection of informatics, emerging technologies, and the extended use and interpretation of specimens and archived databases. This paper explores the potential for transformative research in ecology integrating biodiversity collections, stable isotope analysis (SIA), and environmental informatics. Like genomic DNA, SIA provides a common ‘currency’ interpreted in the context of biogeochemical principles. Integration of SIA data across collections allows for evaluation of long-term ecological change at continent-wide scales. Challenges, including analysis of sparse samples, lack of isotopic baselines, and effects of preservation remain but none are insurmountable. The general research framework proposed here interfaces with databases and observatories, such as the National Ecological Observatory Network (NEON), to provide baselines for retrospective studies and ecological forecasting. Collections and SIA add historical context to fundamental questions in freshwater ecological research, baselines for ecosystem monitoring, and a means of quantitative assessment for ecosystem restoration.

The rivers found in the eight countries in southern North America are exceptionally ecologically and culturally diverse. In this chapter, we focus on a small number of the rivers found in the largest of these countries, Mexico. Remarkable variation in climate and topography generates differences in orographic factors that produce diverse precipitation regimes throughout the country, subsequently influencing patterns in runoff and temporal and spatial variation in Mexican rivers (Hudson et al., 2005; INEGI, 2020a). Mexico is 1.96 million km2, or approximately only20% the size of the United States, yet it is home to 84% of the total number of Level II ecoregions found in the United States and is characterized by exceptional heterogeneity in surface water resources. Some of the wettest (e.g., the Lacand´on Forest in Chiapas) and driest (e.g., the deserts of Sonora) places on the continent are found in Mexico. The Mexican population is growing and so is the Mexican economy (World Bank, 2020). As seen in many regions of the world, the population is urbanizing with growth concentrated in larger cities; approximately 80% of the Mexican population is urban. Population density is approximately 65 people/km2, and annual population growth is currently estimated to be 1.1%. Like many other North American basins, agricultural development, industri-alization, and hydroelectric development threaten the quality and quantity of water flowing through Mexican rivers. Mexico is currently home to at least 25 major Indigenous groups (INEGI, 2020a), many of whom also have long and complex relationships with rivers and streams. It is widely accepted that land-use change and infrastructure development by early civilizations had large impacts on basin-level processes. The Olmec, the earliest known major civilization in Mesoamerica, constructed the first conduit drainage system in the Americas (Doolittle, 2011). As it still does today, forest conversion to slash and burn agriculture by early Mexican civilizations accel-erated soil erosion, potentially compromising freshwater quality. The Mayans reached a population of approxi-mately five million people, peaking around 700 CE They depended on travel and trade conducted along the Grijalva-Usumacinta River, one of the largest drainages in Mesoamerica (Beach et al., 2015).

Insular habitats have played an important role in developing evolutionary theory, including natural selection and island biogeography. Caves are insular habitats that place extreme selective pressures on organisms due to the absence of light and food scarcity. Therefore, cave organisms present an excellent opportunity for studying colonization and speciation in response to the unique abiotic conditions that require extreme adaptations. One vertebrate family, the North American catfishes (Ictaluridae), includes four troglodytic species that inhabit the karst region bordering the western Gulf of Mexico. The phylogenetic relationships of these species have been contentious, and conflicting hypotheses have been proposed to explain their origins. The purpose of our study was to construct a time-calibrated phylogeny of Ictaluridae using first-occurrence fossil data and the largest molecular dataset on the group to date. We test the hypothesis that troglodytic ictalurids have evolved in parallel, thus resulting from repeated cave colonization events. We found that Prietella lundbergi is sister to surface-dwelling Ictalurus and that Prietella phreatophila + Trogloglanis pattersoni are sister to surface-dwelling Ameiurus, suggesting that ictalurids colonized subterranean habitats at least twice in evolutionary history. The sister relationship between Prietella phreatophila and Trogloglanis pattersoni may indicate that these two species diverged from a common ancestor following a subterranean dispersal event between Texas and Coahuila aquifers. We recovered Prietella as a polyphyletic genus and recommend P. lundbergi be removed from this genus. With respect to Ameiurus, we found evidence for a potentially undescribed species sister to A. platycephalus, which warrants further investigation of Atlantic and Gulf slope Ameiurus species. In Ictalurus, we identified shallow divergence between I. dugesii and I. ochoterenai, I. australis and I. mexicanus, and I. furcatus and I. meridionalis, indicating a need to reexamine the validity of each species. Lastly, we propose minor revisions to the intrageneric classification of Noturus including the restriction of subgenus Schilbeodes to N. gyrinus (type species), N. lachneri, N. leptacanthus, and N. nocturnus.

Fish occurrence data are widely scattered and mostly not published as data readily utilizable by computers. Global biodiversity aggregating services (e.g. GBIF, iDigBio, Fishnet) now aggregate and serve whatever data are submitted to them in the standard Darwin Core format, but their data are often replete with errors, minimally normalized, lacking content across standard fields, and served via generic mapping services lacking linkages to local and aquatic ecology-relevant resources (i.e., for fishes, they are ignorant of hydrography). In contrast, Fishes of Texas (FoTX) includes the same data and much more, including unpublished data from more diverse sources. FoTX’s rigorous quality-control measures, including specimen-based ID verifications, checking of legacy georeferencing, and flagging suspicious records has combined to greatly reduce errors. The custom FoTX website provides interactive exploration and data summarization, within the context of geopolitical and, now geographically-expanded hydrographic coverages, thus facilitating visualization and discovery of conservation-relevant histories and trends over time. The site allows viewing of derivative products, such as niche models, estimates of native ranges, checklists, data dashboards, and Native Fish Conservation Areas. The site also serves extensive image collections, collectors’ field notes, and links to digitized, formerly inaccessible unpublished agency reports. Finally, core FoTX data fields are also published to GBIF as Darwin Core to make it available to the world.

For centuries, a taxonomic and alphabetic arrangement (TAA) of objects on shelves prevailed in fluid-preserved natural history collections while they were managed mostly by scientists for their own or vistors’ on-site research using physical specimens. However, most modern collections are now databased and internet-accessible, facilitating diverse forms of research accomplished remotely and decreasing the frequency of need for physical access to specimens, yet the way specimens are shelved and accessed remains nearly universally unchanged. With our fish collection struggling with both severe space limitation and unprecedented rapid growth supporting externally funded research that requires rapid specimen processing and data publication, we started shelving in an object (jar) and catalog number-based arrangement (OCA). To make that possible in our limited and near-full space, without altering our physical shelves in any way, we eliminated all between-jar spaces in our collection, including the customary space between taxa, while keeping it in its original TAA-based order (thus eliminating TAA-based growth capacity. In the resultant empty shelf space, we implemented an OCA shelving system for all newly cataloged jars. Once the OCA contained a relatively large number of jars, we carried out pragmatic, TAA-OCA comparisons. Volumetric jar storage capacity in the OCA is 17% \textgreater TAA, and adjusting the OCA’s vertical shelf spacing to optimizefor each of our 3 jar sizes (impossible in the TAA), could increase that to 115% \textgreater TAA. Ten of 15 routine staff tasks were more efficiently accomplished in the OCA than in the TAA, and the OCA greatly decreases shelving errors (misplacement). We discuss ways to improve efficiency in the OCA for the 5 tasks on which the TAA out-performed it, and report ancillary, unanticipated benefits, such as a way to much more efficiently and quickly monitor fluid levels across all jars. All newly cataloged specimen jarscontinue going into our OCA, and we have significantly postponed hitting the point of absolutely being unable to continue growing. We are hopeful that eventually, a move to a new space will enable conversion of the entire collection from TAA to a more fully-optimized OCA.

We provide an updated overview of the taxonomic and conservation status of all North American blind Ictalurids, and continuing efforts to better understand them. In Texas’ deep Edwards Aquifer under San Antonio, Satan eurystomus (Widemouth Blindcat) has not been collected since 1984, but fragments of Trogloglanis pattersoni (Toothless Blindcat) continue to appear occasionally from the only well still consistently available for sampling, providing material for its recently published complete mitogenome. A metabarcoding-based eDNA sampling project hoping to detect blindcats (and other taxa) is now in early testing in wells throughout the San Antonio area. Lack of access to wells remains a major roadblock for that effort, but we have promising outreach efforts developing that we hope will open doors for sampling in the near future. In the adjacent transboundary Edwards-Trinity Aquifer, new localities have been found for Prietella phreatophila (Mexican Blindcat) in both Coahuila and Texas, and a captive colony at San Antonio Zoo continues to thrive and grow. Two complete mitochondrial genomes from 2 specimens of this species using different methodologies are now available. We present new CT data that indicate specimens from a cave \textasciitilde25 km N of the type locality of Prietella lundbergi (Phantom Blindcat) in Tamaulipas, México, initially reported as that species, represent an undescribed taxon. Multiple attempts by divers to obtain additional specimens of P. lundbergi from the type locality have failed, leaving the formalin-preserved holotype as the only specimen of that species.

Mexico is a country of exceptional physiographic diversity, and the heterogeneity of surface- water resources in the country is remarkable. Some of the wettest (e.g., the Lacandón Forest in Chiapas) and driest (e.g., the deserts of Sonora) places on the North American continent are in Mexico. Mexico is also home to a great diversity of indigenous cultures, many of which have long and complex relationships with rivers and streams. In this chapter, we describe eight rivers: Río Fuerte, Río Salado, Río Nazas-Aguanaval, Río Tamesí, Río Balsas, Río De la Sierra, Río Lacantún, and Río Hondo. The basins we selected are distributed throughout the country and have diverse drainage patterns; some are endorheic, and others drain into the Pacific Ocean, the Gulf of Mexico, or the Caribbean Sea.

Mexico is a country of exceptional physiographic diversity, and the heterogeneity of surface- water resources in the country is remarkable. Some of the wettest (e.g., the Lacandón Forest in Chiapas) and driest (e.g., the deserts of Sonora) places on the North American continent are in Mexico. Mexico is also home to a great diversity of indigenous cultures, many of which have long and complex relationships with rivers and streams. In this chapter, we describe eight rivers: Río Fuerte, Río Salado, Río Nazas-Aguanaval, Río Tamesí, Río Balsas, Río De la Sierra, Río Lacantún, and Río Hondo. The basins we selected are distributed throughout the country and have diverse drainage patterns; some are endorheic, and others drain into the Pacific Ocean, the Gulf of Mexico, or the Caribbean Sea.

This dataset provides location information and some limited attributes of known and potential ciénegas in the Madrean Archipelago ecoregion and closely surrounding area. This was created using point data and information provided by Dean Hendrickson and Thomas Minckley, combined with potential locations derived from analysis of classified raster land cover images and other specialized datasets. Ciénegas, as defined here, are wetlands in arid and semi-arid regions associated with groundwater or lotic components that ideally result in perennial waters on temporal scales of decades to centuries. Ciénegas are typically located at elevations ranging from 0 to 2000m. Ciénegas are typified by significant differences in flora and fauna relative to the greater terrestrial conditions in the region in which they are located. Ciénegas are freshwater to brackish North American wetlands associated with fluvial systems of arid/semi-arid areas of the southwestern U.S. and northwestern Mexico. Once extensively utilized by the region's indigenous human cultures, as well as early European explorers and settlers, the extent of these aquatic riparian communities has dramatically decreased from historic conditions. These communities are now considered imperiled in North America. The data were collected to provide an up-to-date inventory of ciénegas, along with the locations of potential ciénegas, in the Madrean Archipelago ecoregion (and surrounding 15km buffer) in the US and Mexico. This database is meant to bring attention to ciénegas and ultimately prompt more research and restoration activities on these rare and vulnerable ecosystems. The point data are not meant to provide the precise location, but rather depict a general location. The locations of potential ciénegas were calculated as the centroid of the associated, classified raster image pixels or vector polygons. These points would, therefore, not be ideal as target information for a supervised classification of remotely sensed data. This dataset, however, is useful for locating ciénegas for further research, analysis, management and restoration. Additionally, this census of known and potential ciénegas provides a regional geospatial overview of this important ecosystem that few resources can match. In the near future, moreover, we are intending to perform a landscape change analysis focused on ciénegas of the greater Madrean Archipelago ecoregion.

Cienegas, as defined here, are wetlands in arid and semi-arid regions associated with groundwater or lotic components that ideally result in perennial waters on temporal scales of decades to centuries. Cienegas are typically no lower than 0 m, and higher than 2000 m, rarely lower but sometimes higher elevation localities occur. Cienegas are typified by significant differences in flora and fauna relative to the greater terrestrial conditions in the region in which it is located. Cienegas are freshwater to brackish North American wetlands associated with fluvial systems of arid/semi-arid areas of the southwestern U.S. and northwestern Mexico. Once extensively utilized by the region's indigenous human cultures, early European explorers and settlers, the extent of these aquatic riparian communities has dramatically decreased from historic conditions and the community is now considered imperiled in North America. This dataset provides location information and some limited attributes of cienegas in the southwestern U.S. and northern Mexico. There is no information as to the size of the cienega and other important attributes.

Video of presentation in invited webinar (CCAST - also at https://www.youtube.com/watch?v=l9UIVTxZMnw) - Since 2006, the Fishes of Texas Project at University of Texas Austin has sought to improve freshwater fish occurrence data for the state of Texas and make it openly accessible to facilitate research and improve aquatic resource management. Seven federal and state sponsors have contributed funding, but 73% of the total \$2.7 million has come from US Fish and Wildlife Service’s State Wildlife Grant Program via Texas Parks and Wildlife Department. Initially the Project focused on data digitization and compilation of strictly specimen-vouchered data, followed by georeferencing and development of an interactive website/database (http://www.fishesoftexas.org). More recently, non-vouchered citizen science, angler-based, and agency datasets have been added, thereby increasing both geographic and temporal density of records, and a selected subset of data fields for all records is now published to GBIF and iDigBio.

Video of presentation at meeting - Since 2006 the Fishes of Texas (FoTX) Project at University of Texas Austin (UT) has sought to improve freshwater fish occurrence data for the state of Texas and make it openly accessible to facilitate research and improve aquatic resource management. Seven federal and state sponsors have contributed funding, but 73% of the total \$2.7 million has come from US Fish and Wildlife Service’s State Wildlife Grant Program via Texas Parks and Wildlife Department (TPWD). Initially the Project focused on data digitization and compilation of strictly specimen-vouchered data, followed by georeferencing and development of an interactive website/database (http://www.fishesoftexas.org). More recently, non-vouchered citizen science, angler-based, and agency datasets have been added, thereby increasing both geographic and temporal density of records, and a selected subset of data fields for all records is now published to GBIF and iDigBio. The project’s comprehensive data aggregation (44 contributing collections), digitization, normalization, accessibility and high data quality (based, in part on extensive taxonomic determination verification via specimen examination), enabled significant advances in detection and awareness of statewide faunal trends that led to implementation of diverse management advances. Examples include improved field guides and documentation of species’ ranges, expansions and contractions, community composition shifts, improved species conservation status assessments, and documentation of both long-term expansions of invasive species and new introductions. Relatively new to the Project are statewide aquatic bioassessments - intensive fieldwork planned using tools available in our website that facilitate exploration of geographic and temporal sampling histories and reveal under-sampled areas. Consequently, gaps in knowledge of regional faunas have been steadily decreasing. The website and database are widely used; 90% of presentations on related topics at last year’s statewide fisheries meeting utilized FoTX products. This now long-term, consistent funding created a productive partnership between UT and TPWD. With the Project’s bioassessments generating specimens, and TPWD’s independent routine fish sampling increasingly depositing specimens, our collection (TNHCi - https://www.gbif.org/dataset/6080b6cc-1c24-41ff-ad7f-0ebe7b56f311) has nearly doubled in size over the last decade. Last year, TPWD’s list of Species of Greatest Conservation Need was updated, with major changes based on the improved knowledge provided by FoTX. TPWD now funds a full-time Assistant Collection Manager position focusing on bioassessments, but also doing basic collection management and supervision of student and volunteer help. Another grant-funded position, a liaison between the collection and TPWD staff, spawned the ongoing statewide Texas Native Fish Conservation Areas program that coordinates funding and actions of diverse stakeholders for watershed-scale conservation. Both externally funded UT positions participate in diverse collections-based research and outreach endeavors for both UT and TPWD. The FoTX website was developed in large part by staff in UT’s science database group in the Texas Advanced Computing Center (TACC) - a collaboration that blossomed into long-term technical support for collection database management and data publication that has since expanded to support all other collections in UT’s Biodiversity Center.

Each field has its pioneers, and the field of desert fish conservation is no exception. Efforts to conserve aquatic life in the desert have been fueled equally by the ecological understandings developed by science and conservation actions directed by firmly held ethical beliefs. A few individuals are capable of combining scientific knowledge and conservation ethics into an undeniable passion that becomes contagious. These pioneering giants marveled at the ability of certain species to survive in seemingly harsh environments and, when necessary, mounted a vigorous defense when outside forces threatened their survival. This chapter traces the careers of a small handful of highly dedicated and influential scientists who recognized the value of desert fishes and came to their aid at a time when few cared for, or even knew of, such species. They saved species and habitats while influencing so many to follow in their footsteps. In this chapter, the legacies of eight giants in the field desert fish conservation are honored, and it is hoped that through these biographies they will continue to inspire new professional, ethical, committed warriors to join the battle against extinction.

Yaqui Catfish Ictalurus pricei is an understudied species with limited information of its ecology, distribution, and local habitat use. Native to the southwest United States and northwest Mexico, Yaqui Catfish populations are declining which has prompted the species to be listed as threatened in the United States and a species of concern in Mexico. Water over-allocation, habitat degradation, invasive species introductions, and hybridization with non-native Channel Catfish I. punctatus have caused the populations in Mexico to decline. The United States population collapsed after years of low recruitment. To better focus conservation efforts, as well as define habitat associated with Yaqui Catfish occurrences, we assessed the distribution in the Yaqui River Basin of Mexico using historical data at a landscape scale. Yaqui Catfish were historically found across the watershed among a diversity of environments, but most frequently associated with small, intermittent streams. Basin landcover was dominated by forest, shrubland, and grassland and Yaqui Catfish generally occurred in stream segments in similar proportions. However, a small number of Yaqui Catfish occurrences were associated with urban and cropland landcover types greater than that which was present on the landscape. With the species facing declines in the region, this work will help inform future conservation efforts aimed at securing this species, protecting suitable habitat and better defining its current status in Mexico.

The Rio Grande Cichlid, Herichthys cyanoguttatus, is native to the drainages of the Gulf Coast of northern Mexico and southern Texas and has been introduced at several sites in the US. Previous observations have suggested that non-native populations in Louisiana that are currently recognized as H. cyanoguttatus resemble another species, the Lowland Cichlid, H. carpintis. Traditional morphological and genetic techniques have been insufficient to differentiate these species, but H. carpintis has been reported to differ from H. cyanoguttatus in color pattern, so we turned to novel electronic photo archives to determine the identity of the species introduced in Louisiana. First, we used the public databases Nonindigenous Aquatic Species Database and Fishes of Texas to infer the historical distributions of these species in the US. We then used museum specimens, live specimens, and two additional databases, The Cichlid Room Companion and iNaturalist, to compare morphology and color patterns among individuals obtained from their native and introduced ranges in Mexico, Texas, and Louisiana. Our general observations found that H. cf. cyanoguttatus from Louisiana tended to have an obliquely oriented mouth and a more rounded ventral profile than H. cyanoguttatus from Texas, consistent with previous descriptions of H. carpintis, but our morphological analyses were unable to identify any significant differences among populations. Our analyses of color patterns found that H. cf. cyanoguttatus from Louisiana had larger iridescent spots than H. cyanoguttatus from Texas as well as black breeding coloration that extended anteriorly to the tip of the mouth, characters consistent with H. carpintis. Our observations indicate that at least some of the cichlids introduced in Louisiana are not H. cyanoguttatus but are instead H. carpintis, and that their presence there is likely due to release by humans. This is the first record of H. carpintis establishing a population in the US. Understanding the biology of not one, but two, species of Herichthys will be necessary to predict and mitigate their continued colonization of new environments in the US.

The Rio Grande Cichlid, Herichthys cyanoguttatus, is native to northeastern Mexico and southern Texas and has been introduced at many places in the US. Recent research has indicated that the true identity of at least some populations of Herichthys cf. cyanoguttatus in Louisiana is H. carpintis and not H. cyanoguttatus. In both their native and introduced ranges, H. carpintis seems to occupy a more lowland/coastal distribution than does Herichthys cyanoguttatus, suggesting that the two species may differ physiologically or ecologically in their ability to invade new environments. Previous research has found that Herichthys cf. cyanoguttatus from Louisiana (which were most likely H. carpintis) have a high tolerance to salinity and pose a threat to both fresh and brackish waters, but the osmoregulatory capacity of H. cyanoguttatus from Texas is unknown. To determine if H. cyanoguttatus from Texas might also have a high tolerance to salinity and pose a threat to both fresh and brackish waters, we performed three experiments to assess response to salinity challenges in H. cyanoguttatus from Texas and in H. carpintis from Louisiana. In response to acute moderate salinity challenge, we found a non-significant salinity*species interaction in change in body mass, a species difference in hematocrit, and no differences in plasma chloride or osmolality. In a 120-day chronic salinity exposure, salinity concentration was inversely related to growth rate, but there was no difference in growth between the two species. In an acute challenge, high salinity concentrations had a strong negative effect on survival, but survival was not different between the two species. Both species were highly tolerant of salinity, indicating that both species might be able to use brackish waters in coastal areas to expand their ranges in the US. Finally, we found that H. cyanoguttatus from Texas spent more time swimming than did H. carpintis from Louisiana, suggesting that the two species could differ in the way they interact behaviorally with native fish communities.

A taxonomic and alphabetic arrangement (TAA) of objects on shelves has prevailed in fluid-preserved natural history collections while they were managed by scientists for their own research. Now most collections are databased and internet-accessible to facilitate very different forms of research accomplished remotely by researchers who require less physical access to specimens. The collections staff who make those data available struggle to manage collection growth with limited space and budgets, while demands on them are increasing, necessitating task and space-efficient collection management solutions. We describe an alternative arrangement of objects based on their size and catalog number (OCA) that capitalizes on modern databases. Our partial implementation of this system facilitated pragmatic between-system comparisons of space use and staff time required for routine tasks. Our OCA allows 17% more jars to be stored in a given space than a TAA (not counting spaces left for growth), but adjusting vertical spacing of shelves could increase that to 115%. Ten of 15 staff tasks were more efficiently accomplished in the OCA section of the collection, and we propose ways to improve efficiency for three of the four tasks for which the TAA outperformed the OCA.